Fiber optic cables usually are constructed in a plurality of concentric layers. Typically, in the center is a single optical fiber or a bundle of such fibers encapsulated by a plastic buffer tube, which is in turn encircled by a plurality of longitudinally extending strength members. These strength members can be formed of plastic or metallic strands. Enclosing the strength members is a plastic outer tubular jacket. To save space and avoid expense, these various layers usually are not adhered to one another.
With the increased use of such fiber optic cables, a great demand presently exists for devices that can safely grip such cable to pull them through conduits or to support the cable in an upright position. While various prior art devices are known for gripping and pulling electrical cable, which use wire mesh sleeves, these prior art devices are not totally acceptable for use with fiber optic cable. Basically, their use alone with such cable is inadequate since gripping the fiber optic cable outer jacket with the wire mesh sleeve tends to extrude the jacket over the inner components of the cable when the cable is under high tension loads. Examples of such conventional wire mesh sleeves utilized with electrical cable are disclosed in U.S. Pat. Nos. 1,686,250 to Page; 1,807,993 to Martin; 2,740,178 to Kellems; 2,766,501 to Kellems; and 3,122,806 to Lewis. An example of a grip utilizing a wire mesh sleeve for specifically gripping fiber optic cable is disclosed in U.S. patent application Ser. No. 213,856, filed on Dec. 8, 1980 in the name of Alfred W. Fidrych and now U.S. Pat. No. 4,368,910, issued on Jan. 18, 1983. While this application does disclose the use of wire mesh grips with fiber optic cable, the only connection between the grip and the cable is the wire mesh sleeve. Thus, there can be a potential extruding of the outer jacket if the cable is under high tension loads. In U.S. patent application Ser. No. 340,900, filed on Jan. 20, 1982 in the name of Alfred W. Fidrych, and now abandoned, a gripping device for fiber optic cable is disclosed which attaches the cable to a connector. The gripping device includes a tubular support member, a wire mesh sleeve coupled thereto for gripping the outer surface of the cable and a mechanism for rigidly coupling the longitudinal inner strength member in the cable to the support member.
In all events, there is a continuing need for devices that can safely grip and pull fiber optic cable which do not damage the fragile cable's ability to transmit light or extrude the outer jacket relative to the inner core.